The present invention relates to armor-piercing projectiles and more specifically to an armor-piercing body intended to be fitted on very long projectiles .
An armor-piercing projectile is a round intended to pierce the sheet plating which provides protection for a wide variety of vehicles or shelters. These sheet plates, called armor-plating, are made of a material such as steel, suitably alloyed and treated. The primary effect sought in armor-piercing projectiles is the penetration of the armor-plating; their destructive power is supplied by secondary effects, such as the ejection of material inside the shelter or by combination with the projectile of elements able to produce complementary effects such as fires.
Armor-piercing munition can be divided into two main classes;
Armor-piercing projectiles, characterized by a length having an aspect ratio of three to five times the diameter, fired by a cannon with a rifled bore, which provides gyroscopic stability during the trajectory; PA1 Armor-piercing arrows, characterized by a length having an aspect ratio of ten to fifteen times the diameter, fired or ejected from a cannon with a smooth bore, stability during the trajectory being obtained by the addition of stabilizer fins. PA1 The arrow body which has a very high mechanical resistance, PA1 The stabilizer fins which are usually provided at the rear of the body, PA1 An aerodynamic cap which covers the front part of the body. PA1 The speed, the mass and the caliber of the arrow body at the instant of impact on the armor-plating, PA1 The mechanical resistance of the arrow body to the shock and penetration.
The invention concerns the latter class more particularly.
An armor-piercing arrow generally has three elements:
The theory of armor-piercing projectiles is fairly well established. In particular, it is known that the main parameters governing the perforating power of the weapon are:
As a result, for a given arrow body speed upon impact and a given caliber, the perforating power thereof can be increased by increasing the mass of the body.
If the projectile caliber is fixed, a known means of increasing that mass is to alter the aspect ratio and simultaneously to choose a material which combines the required mechanical qualities with a high density. These considerations are not independent; in particular, increasing the length calls for an increase in the mechanical resistance qualities.
The application of the above considerations becomes difficult when the operational conditions of firing are taken into account. It is desirable that the arrow body piercing power remain satisfactory over a wide range of incident angles on impact. In particular, the mechanical forces developed during the armor-piercing phase, especially at high incident angles, limit the maximum aspect ratio to values between 12 and 15 times the diameter.
The only variable parameter available, with speed, caliber, and aspect ratio fixed, is the specific weight or mass of the material used for the construction of the body. Unfortunately, those materials with a high specific weight do not have intrinsically the mechanical characteristics required and necessary to prevent the break-up or buckling of the arrow during armor-piercing. To improve the mechanical resistance of certain high density materials, it is known that the arrow body thus formed can be subjected to certain treatment. These operations are relatively critical and complex and, as a result, lead to high production costs for the projectile.